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1991 Cadillac Fleetwood Question: Failed No's toohigh



Ices, El Sobrante, CA, March 05, 2011, 00:55

Everything passed except failed smog no's too high

2 Answers
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  • Answer #1

    March 05, 2011, 02:33

    I believe you need to be looking at reasons your engine is running lean, creating a high amount of oxygen in your exhaust gas. This could be due to an air intake leak, a vacuum leak, or a sluggish oxygen sensor (or two). Some folks change catalytic converters for this - I would not do that unless you find that testing indicates the catalyst efficiency is compromised. Good luck.

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  • Reply

    Ices, March 06, 2011, 18:22

    Thanks, I have changed the Oxygen Sensor check for vacuum leaks and do a retest tomorroww.

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  • Answer #2

    Rainbowauto from Rainbow Auto Center, March 07, 2011, 16:03

    Need more inforamtion onthe car,but usually first thing I would suspect is the egr system,timing too far advanced, cataltic converter....good luck

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